The reaction between m-cresol and N,N’-dimethylolthiourea gives a novel m-cresol-Dimethylolthiourea (MCDMTU) oligomers. These oligomer then treated with various aromatic diazonium salts afforded a series of novel oligomeric acid azo dyes. The newly formed compounds were characterized by dyeing assessment properties on various textile fibers, which was excellent. The dyes fixed on the fiber with almost negligible unused dye. Most of the dyes have high fixation on textile at less percentage of exhaustion. While using these dyes commercially, it may affect the environmental saving by less percentage of dye effluents from textiles.